The knowledge of the geometrical and construction characteristics and those related to the strength of materials, is useful to determine the dynamic behavior of existing buildings, characterized by a wide range of uncertainties related to geometrical irregularities, imperfections, past damages and also by the state of material conservation. The purpose of this study is a primary estimation of the most influential parameters on a brick work prism subjected to the uniaxial compression test through a method of experimental design carried out on a numerical model.